1. Technical Field
The present invention relates to a detection device, a sensor, an electronic apparatus, a moving object, and the like.
2. Related Art
In an electronic apparatus such as a digital camera, a smart phone, or a moving object such as a car, or an airplane, a gyroscope sensor for detecting a physical quantity which is changed due to an external factor is embedded. Such a gyroscope sensor detects a physical quantity such as angular velocity, and is used in a so-called camera shake correction, a posture control, a GPS autonomous navigation, and the like.
As one of these gyroscope sensors, a vibrational gyroscope sensor such as a crystal piezoelectric vibrational gyroscope sensor has been known. The vibrational gyroscope sensor detects a physical quantity corresponding to Coriolis force which occurs by rotation. As a detection device of the vibrational gyroscope sensor, for example, technologies disclosed in Japanese Patent No. 4930253, JP-A-2006-29901, and Panasonic Technical Journal Vol. 58 No. 1 Apr. 2012, “Development of Consumer 3-Axis Angular Velocity (Motion) Sensor”, SAKAKI, FUJII, YOSHIUCHI, MORINAKA, NAKAMURA, and YAMASAKI have been known.
In the technology disclosed in Japanese Patent No. 4930253, a vibrator is driven by a drive signal of a rectangular wave of which an amplitude is controlled by an AGC circuit. However, the drive signal of a rectangular wave includes many harmonic components, and thus a detection performance of a detection device is degraded due to the harmonic component.
On the other hand, in the technology disclosed in Panasonic Technical Journal Vol. 58 No. 1 Apr. 2012, “Development of Consumer 3-Axis Angular Velocity (Motion) Sensor”, SAKAKI, FUJII, YOSHIUCHI, MORINAKA, NAKAMURA, and YAMASAKI, an output signal of an AGC circuit is input into a band pass filter, and the signal after being subjected to a band pass filter processing is output to a vibrator as a drive signal. By performing such a band pass filter processing, it is possible to eliminate harmonic components other than a drive frequency component, and thus it is possible to inhibit a detection performance of a detection device from being degraded due to the harmonic component to a certain extent. However, in order to obtain a drive signal of a sine wave which has small distortion by the band pass filter processing, a band pass filter of a narrow band is necessary, and thus it is not easy to design the detection device, and it is difficult to sufficiently reduce the harmonic component of the drive signal.
In addition, in the technology disclosed in JP-A-2006-29901, two piezoelectric elements are formed on a first side surface of a vibrator, and an output signal of an oscillation circuit is input into a second side surface facing the first side surface. Then, output signals of the two piezoelectric elements are added by an adding circuit, and an added output signal is output to the oscillation circuit, and thus a drive signal of a sine wave is obtained. However, in the related art, in order to obtain the drive signal of a sine wave, a vibrator in a special structure is necessary. In addition, in any of Japanese Patent No. 4930253, JP-A-2006-29901, and Panasonic Technical Journal Vol. 58 No. 1 Apr. 2012, “Development of Consumer 3-Axis Angular Velocity (Motion) Sensor”, SAKAKI, FUJII, YOSHIUCHI, MORINAKA, NAKAMURA, and YAMASAKI, a design concept of the drive signal of a sine wave in which a relationship between an equivalent series resistance and a negative resistance of the vibrator is considered is not disclosed.